Diethyl 1-(4-methyl-phen-yl)-3-phenyl-5-oxopyrrolidine-2,2-dicarboxyl-ate.

In the title compound, C(23)H(25)NO(5), the lactam ring adopts an envelope conformation and both eth-oxy-carbonyl side chains show an s-cis conformation: one is nearly planar, the dihedral angle between CO(2) and OCH(2)CH(3) groups being 7.95 (14)° and the other is almost orthogonal, the C-O-C-C torsion angle being 85.33 (9)°. Dimers related by inversion symmetry are stabilized by C-H⋯O hydrogen bonds. The crystal structure is consolidated by weak intermolecular C-H⋯O inter-actions. Weak intra-molecular inter-actions of the same kind also occur.